Baidu Inc. returned to profit growth in the third quarter and offered a bullish revenue outlook for the fourth, as the Chinese search giant found ways to make more money from its network of advertisers.

China's largest search-engine business by revenue reported a 1.3% rise in net profit, compared with the second quarter's 4.5% drop. Baidu also gave better than expected fourth-quarter revenue guidance of between 9.22 billion yuan...